Juuou Mujin no Fafnir

Second Lieutenant Yuu Mononobe arrives at Midgard, an all-girls school where students with “D” powers train to fight dragons. His sister Mitsuki, the student council president, is also among those with these abilities. At school, Yuu meets Iris Freya, a classmate struggling with her “D”-related studies, and the two become friends. Together, they try to succeed in a dangerous world where their powers are needed to face dragons.